Charge and save

Charge and save

THE GP JOULE MAGAZINE NO. 15 / JANUARY 2024

Fast charger with storage as well as a dynamic electricity tariff – a combination which makes e-vehicles charging much more cost-effective.

GP JOULE is now offering customers a bundle which consists of a fast charger, billing and communications solutions, as well as a dynamic electricity tariff. The charging station is equipped with a battery; this makes it possible to store electricity when it is cheap – and also to achieve very high charging performance even on low-voltage networks with limited connection capacity.

What can you expect to pay for a bowl of strawberries? It all depends on the time of year: when the fields are full of fruit in summer, even though strawberry demand is high supermarket customers will pay far less for them than they do in winter, when supply is scarce – the mechanism is straightforward.

With electricity the situation is generally a bit different: when wind turbines and photovoltaic systems are generating a lot of energy, retail prices on the power exchange spot market tend to plummet. But customers don’t benefit from that at all, because their energy tariffs are usually fixed – at least in Germany. So if you are charging an electric vehicle, or are an operator purchasing energy for publicly accessible charging points, you will pay the standard price even if electricity is available on the exchange very cheaply at that moment.

This discrepancy has motivated GP JOULE to put together a new electromobility package which enables charging station operators as well as their customers to benefit from what the power market is doing: a bundle consisting of a fast charging station and solutions for billing and communication, plus a dynamic electricity tariff that follows the spot market price.

Anyone who buys power specifically when the exchange price is low will noticeably reduce their costs: “Our dynamic tariff almost always results in a saving of at least 50 cents per charging process when charging electric cars, and sometimes much more,” said Dr. Fabian Sösemann, Managing Director of GP JOULE PLUS, which is responsible for electricity retail.

What’s more, power at these times is not only cheap but also green, as Sösemann emphasised: “After all, what lower prices mean is that there is a lot of wind and solar power in the grid.” So by aligning their power consumption with the spot market, customers will significantly reduce their carbon emissions.


Price advantages for companies and end customers

Operators of electric commercial vehicle fleets, such as logistics businesses, can use dynamic tariffs to markedly reduce their power costs by shifting their charging processes to favourable times – taking into account operational framework conditions. Given that downtimes and energy requirements can generally be well-predicted, there is great potential here. And operators of public charging points can also benefit, as it brings down their procurement costs. “They can pass on savings to their customers via our dynamic end customer tariffs, which gives them a competitive advantage,” explained Dr. Hans Henning Thies, Head of Business Field Development of GP JOULE CONNECT, which specialises in electromobility.

These tariffs continually track what is happening on the energy exchange spot market. Alternatively there is the option to derive the tariff level based on anticipated charging point capacity utilisation, taking into account traffic flows, holiday times and other factors.

Given that dynamic tariffs require more price information to be transmitted to end customers, GP JOULE CONNECT ensures that charging points and all the necessary associated data are displayed in apps such as Moovility, in digital maps such as Apple Maps, and in-car navigation systems. “This is how we guarantee the necessary visibility of all charging points,” Thies reported. Billing and payment are dealt with by direct payment via a backend developed by GP JOULE CONNECT.


Fast charging with integrated battery

However, not every charging process can be shifted to low-price phases. An electric public bus or transporter van, for example, has to be at the depot with a full battery in the morning, no matter what the spot market price was the previous night. This is why GP JOULE equips its customers with ADS-TEC fast charging stations that feature an integrated lithium-ion battery. With a footprint of just two square metres, these stations facilitate charging with 300 kilowatts of power. The “made in Germany” fast chargers also support two simultaneous charging processes, with each supplied with 150 watts of power.

This gives charging point operators the capacity to fill up charging station storsaving age specifically when power is cheap – generally not during lunchtimes and afternoon hours. This keeps costs low even if the exchange price suddenly rises again – which is great for companies which maintain an electric vehicle fleet, for example.


Rapid and cost-effective connection to the grid

What’s more, the integrated fast charger battery not only facilitates optimum use of the dynamic power tariff, but also enables very high charging power to be offered even on low-voltage grids that have limited grid connection capacity. “Thanks to the integrated battery, operators need not wait for expensive grid expansion before they start their installation,” Thies explained. “This is an advantage, particularly in urban settings where capacity is often scarce.” This could significantly accelerate the establishment of fast charging points. At the same time, the investment outlay required is coming down – which is particularly appealing for companies which do not own the land on which their charging stations are sited, making them reluctant to incur high costs. As an additional advantage, operators avoid higher grid fees if they are able to operate with a lower connection power.

Regardless of grid capacity, making charging stations which are very easy to establish and dismantle contributes to rapid implementation. “Companies can start by testing a single location on their premises. If it turns out that the fast charger would be more usefully located elsewhere, they can move it without major effort,” Thies said.

Operators also benefit from the fact that the charging columns do not need a transformer. This saves space as well as money – an important consideration, particularly for sites in densely populated regions such as city-based filling stations.


A bridge between fast chargers and photovoltaic systems

The integrated battery also means that operators can make more use of solar power for electromobility, by means of their own photovoltaic system. After all, solar power systems generate most energy when the vehicle is generally out and about. Storing energy in the battery means that vehicles can be charged with solar power in the evenings and overnight. To put it another way, this turns the battery pack into a bridge between fast chargers and photovoltaic systems. GP JOULE CONNECT takes care of the controls here.

And not least: at some point in the future, battery storage will be able to help charging point operators implement business models that use bidirectional power flow. “There are still regulatory hurdles to be overcome here,” said Sösemann. “Once these are cleared, there will be huge opportunities for companies.”